TABLE IV.

Particle Characterization Using Digital Images (40× Magnification) of Periprosthetic Tissues from Patients with Uncemented Metal-Backed Cups and Cemented Titanium Stems

Case No.	Particle Density (per mm2)	Median Equivalent Diameter (µm)	Median Circularity	PE density (per mm2)
Uncemented
1	1413	0.57	0.85	1.7
2	14,719	0.36	N/A	1.9
3	1626	0.42	0.95	27.8
4	8114	0.42	1	11.5
5	2641	0.36	1	0.6
6	117	0.47	0.82	0
7	1214	1.05	0.92	7.3
8	5357	0.36	1	3.0
9	N/A	N/A	N/A	23.6
10	1338	0.42	1	4.4
11	69	2.6	N/A	0.2
12	3827	0.52	0.98	24.9
13	185	0.56	N/A	1.7
14	8937	0.42	N/A	1.4
15	1193	0.45	1	2.8
Cemented
16	6897	0.59	N/A	0.6
17	14,922	0.47	N/A	3.6
18	13,041	0.51	N/A	2.8
19	14,727	0.51	N/A	3.0
20	9878	0.51	N/A	2.4
21	32,428	0.51	N/A	2.1
22	3664	0.55	N/A	0.2
23	21,098	1.05	0.86	4.9
24	14,164	0.7	1	0.8
25	9610	0.7	0.83	0
26	33,619	0.51	N/A	0
27	42,675	0.69	N/A	0.2
28	7902	0.42	1	0.3
29	35,592	0.73	0.95	0.9
30	14,987	0.6	0.9	0.3

N/A: Particle characteristic could not be measured appropriately.

Images were taken with High-Resolution Optical Darkfield Microscopy (HR-ODM). Total number of particles, particle density, median equivalent diameter, and median circularity were measured using NIS Elements image analysis software. Polyethylene particles (PE) were counted (total number and particle density) using a polarization microscope with a motorized table.